Simplify Relationship

lib/active_model_serializers/adapter/json_api.rb

@@ -438,14 +438,7 @@ module ActiveModelSerializers
           allow_wildcard: true
         )
         serializer.associations(include_directive).each_with_object({}) do |association, hash|
-          hash[association.key] = Relationship.new(
+          hash[association.key] = Relationship.new(serializer, instance_options, association).as_json
-            serializer,
-            association.serializer,
-            instance_options,
-            options: association.options,
-            links: association.links,
-            meta: association.meta
-          ).as_json
         end
       end
 

lib/active_model_serializers/adapter/json_api/relationship.rb

@@ -6,17 +6,20 @@ module ActiveModelSerializers
         # {http://jsonapi.org/format/#document-links Document Links}
         # {http://jsonapi.org/format/#document-resource-object-linkage Document Resource Relationship Linkage}
         # {http://jsonapi.org/format/#document-meta Document Meta}
-        def initialize(parent_serializer, serializer, serializable_resource_options, args = {})
+        def initialize(parent_serializer, serializable_resource_options, association)
+          serializer = association.serializer
+          options = association.options
+          links = association.links
+          meta = association.meta
           @object = parent_serializer.object
           @scope = parent_serializer.scope
-          @association_options = args.fetch(:options, {})
+          @association_options = options || {}
           @serializable_resource_options = serializable_resource_options
           @data = data_for(serializer)
-          @links = args.fetch(:links, {}).each_with_object({}) do |(key, value), hash|
+          @links = (links || {}).each_with_object({}) do |(key, value), hash|
             result = Link.new(parent_serializer, value).as_json
             hash[key] = result if result
           end
-          meta = args.fetch(:meta, nil)
           @meta = meta.respond_to?(:call) ? parent_serializer.instance_eval(&meta) : meta
         end
 

test/adapter/json_api/relationship_test.rb

@@ -150,9 +150,23 @@ module ActiveModelSerializers
 
         private
 
-        def test_relationship(expected, params = {})
+        def test_relationship(expected, test_options = {})
           parent_serializer = AuthorSerializer.new(@author)
-          relationship = Relationship.new(parent_serializer, @serializer, nil, params)
+
+          serializable_resource_options = {} # adapter.instance_options
+
+          meta = test_options.delete(:meta)
+          options = test_options.delete(:options)
+          links = test_options.delete(:links)
+          association_serializer = @serializer
+          if association_serializer && association_serializer.object
+            association_name = association_serializer.json_key.to_sym
+            association = ::ActiveModel::Serializer::Association.new(association_name, association_serializer, options, links, meta)
+          else
+            association = ::ActiveModel::Serializer::Association.new(:association_name_not_used, association, options, links, meta)
+          end
+
+          relationship = Relationship.new(parent_serializer, serializable_resource_options, association)
           assert_equal(expected, relationship.as_json)
         end
       end